Electric switch



Feb. 11,1936. 5. o. EATON 2,030, 91-

ELECTRIC SWITCH Filed May 31, 1933 Invrit re -.Regiha|d O. Eatph,

His A toth eg.

Patented Feb. 11, 1936 UNITED STATES PATENT OFFICE ELECTRIC swrrcn Reginald 0.1mm, Erie; Pa, assignor to General Electric Company, a corporation of New York Application May 31, 1933,'Seriai No." was nitude much is yet to be desired in the arrangement of the flexible conductor to which are se-- cured the movable contacts. In circuit con-.

trollers of small current capacity the heating of the contacts and the consequent loss of power will be negligible, but in switches where large current is carried the heating and loss of power due to poor contact between the parts is often considerable. .To reduce this heating it is necessary to reduce the resistance of the parts as well as-to insure at all times a minimum contact resistance.

It is therefore a further object of my invention to provide a construction wherein a minimum resistance exists between the movable contacts and their associated stationary conductors.

In carrying out my invention in one form, the movable contact comprises flexible electrical conductors connected together at one end and having 'spaced portions forming contact members, with ing or brazing-to a stationary conductor l5. As,

shown, the flexible conductor II preferably formed of copper or other suitable low-resistance material forms a closed loop above the stationary conductor I5, although the upper bend lid of thisloon can be omitted without departing from my invention. Contact members are secured to the conductor near the upper end of the loop,

i. e., to the spaced portions of the conductor, by I means of the copper tubes l3 and I 3 which tubes are cold forged over the flexible conductor so as to form intimate electrical connection between the tubes and the conductor. The copper spacing blocks 20 and 2| are secured integrally with the tubes l8 and [9 on the outermost sides'of the loop, and the contact members, shown as plates 22 and 23, preferably made of silver, are integrally secured in turn to the spacing blocks 20 and 2|. It will be observed that each contact plate,

9 Claims. (01. zoo- 171) switches prois directly connected to the stationary conductor I! by a separate conductor formed by its branch of the-loop, although by reason of the current path afforded by the upper bend Ila of the loop, current can flow through both branches of the 6 looped conductor to the respective contact plates.

A high contact pressure is secured by means of a spring assembly including a pair of spring seats or guides 25 and 26 secured to the inner sides of the tubes l8 and H. A pair of helical compression springs 28 and 29 mounted on the spring guides, as by lugs carried by the guides and inserted in the ends of the springs, normally exert a pressure in a direction to'separate the contact plates 22 and 23 The spring seats 25 and 26 with the springs 28 and 29 mounted between them are maintained in position and the contact assembly moved as a whole by means of apair of operating arms 32 and 33. These operating arms are identical in construction. It w'ill'be observed'that the operating arm 33 is provided with a rectangular opening 34. through which the notched ends 35 and 36 of the spring seats or guides and 26 extend, and are seated, when the contact member is in open circuit position, against opposite sides 25 of the opening by the pressure of the springs 28 and 29. The opposite ends of the guides 25 and 26 are secured in a similar manner by the arm 32. The movable switch member It can be moved from one circuit controlling position to another into engagement with one or the other of the spaced stationary contacts 40 and 4| by means of an operating member (not shown) secured to and carrying the operating arms 32 and 33, or the switch member can be moved to an intermediate open I circuit position between the two stationary contacts. In closing the circuit by engagement with one or the other of the two stationary contacts, the movement of the arms 32 and33 is continued a short distance after engagement is made with 40 a the stationary contact whereby the springs are compressed somewhat to apply the force of the springs to secure the contacting surfaces together. Itwill be-observed that during this continued movement of the arms 32 and 33 to apply the pressureof the springs to the contacting surfaces, the spring guide 25 'or 26 adjacent the engaged contact plates 22 or 23 slides in the rectangular openings in the arms 32 and 33.

Inasmuch as the compression springs 28 and 29'are located directly back of the contact plates 22 and 23, it will beseen that the contact pres-, sure exerted by these springs serves to maintain the contact plates in engagement with the maxi- -mum surface of the cooperating stationary conchange in the position of the movable contact secured by maintaining the maximum contact area between the stationary and movable contacts.

If the upper bend I la 01 the loop above the contact plates and 21 is omitted, it will be obof my invention, it will be understood of course that I do not wish to be limited thereto since many modifications may be made, and Ithere= fore contemplate by the appended claims to cover any such modifications as fall within; the true spirit and scope of my invention.

What I claim as new and desire to'secure by Letters Patent of the United States is:

1. In a switch, a movable switch member comprising a flexible conductor, a contact plate secured to one side of said conductor, a spring guide secured to the other side of said conductor opposite said contact plate, a compression spring having one end supported by said spring guide, a second spring guide supporting the other end of said spring, and an operating member connected to said spring guides for operating said 7 switch member and for supporting said guides.

, 50. "g conductors, a. compression spring, spring guides 2. In a switch, a movable switch member comprising a flexible conductor, a contact plate secured to one side of said conductor, a spring guide secured to the other side of said conductor opposite said contact plate, a compression spring having one end supported-by said spring guide, a second spring guide supporting the other end 01 said spring, and switch operating arms provided with openings through which adj acent ends of said guides'extend for supporting said guides,

said openings permitting movement of said guides independently of, said arms 'to compress said spring.

3. In a. switch provided with a stationary contact, a movable switch member comprising flexible conductors electrically connected together at onejend and having spaced portions, a movable contact secured to an .outside face of one of said secured to said spaced portions of said conductors for supporting said spring, andan operating member connected to said guides for moving said switch member to bring said movable con-- tact into engagement with said stationary contact and for thereatterapplying the force of said spring to said movable contact, said operating member forming a support for said guides.

4. In an electric switch, stationary contacts therefor, a. stationary terminal member, a. movable switch member comprising a flexible conductor having its ends secured together to form a loop, means for securing said ends oi! said loop to said terminal member, movable contact members secured to opposite sides 01' said loop, a spring associated with said movable contact members for biasing said movable contact members towards said stationary contacts, and an op- -erating arm for said switch member, said operating arm normally restraining said movable contact members against movement by said spring towards said stationary contacts.

v I 2,030,691 plates so that a minimum contact resistance is' 5. In an electrical switch, a pair of stationary contacts, a switch member comprising a onepiece flexible conductor having its ends secured together to form a loop of low electrical resistance, a stationary terminal, means for securing said ends of said loop to said stationary terminal, contact members secured to opposite sides of said loop, biasing means interposed between said contact members, operating means for supporting and moving said flexible loop relative to said stationary terminal, said loop being movable to engage one or the other of said contact members with one or the other of and stationary contact-S, said loop forming a low resistance path to said stationary contacts and preventing heating of said biasing means.

6. In an electric switch, stationary contacts therefor, a movable switch member comprising a flexible conductor having its ends secured together to form a loop, movable contact members secured to opposite sides of said loop, spring guides within said loop and associated with each of said contact members, a compression spring mounted between said spring guides, and ope1"--v guide associated with each of said contact memwithin said loop bysaid spring guides, a pair of operating arms on opposite sides of said loop for supporting said guides and for limiting the action or said compression springs in biasing said contact members away from each other, said operating arms being movable to move said switch member from one position to another and to compress said springs.

9. In an electric switch, a stationary contact, a. cooperating movable switch member comprising a flexible conductor having its ends secured together to ,form a closed loop, a movable contact secured to one face of. said loop, a spring guide within said loop and operatively associated with said contact, a second spring guide on the opposite side of said loop, a compression spring supported within said loop between said spring guides, and an operating member connected to ing member to apply a predetermined pressure to said contacts.-

" I REGINALD O. EATON. 

